Preheating flame stabilizer for cutting blowpipes



Aug. 2 1, 1934. R 1 KEHL 1,971,008

IREHEATING -FLAME STABILIIZER FOR CUTTING 'BLONPIPES` I Filed March s1. 1932 IN JENTOR: /ff

llllml Patented Aug. 21, 1934 UNITED. STATES PREHEATING FLAME STABILIZER FOB CUTTING BLOWPIPES Robert 5J. Kehl, Bayside, N. Y., assignor to Oxweld Acetylene Company, a corporation of West Virginia Application- March 31, i932,l serial No. 602,332 1 acclaim. (c1. s-27.4)

This invention relates to blowpipes and particularly to Oxy-gas blowpipes for use in cutting by means of a preheating flame and oxygen jet and, in which, the cutting oxygen and that for supporting combustion of the preheating gas is supplied from a common source.

In blowpipes of this character, the oxygen to be mixed with the fuel gas is supplied to a mixing chamber by a branch passage constitutingl an oiltake from a main passageI from the source of oxygen supply. Flow of oxygen from'v the main oxygen rpassage to the cutting tip of the blowpipe is through a passage controlled by a valve ordinarily located between the branch passage and the cutting tip, which valve, when opened, robs the branch passage of oxygen causing the pressureV therein to drop. When the valve is again closed, this pressure is, of course,

restored and thus it will appear that the opening and closing of the cutting oxygen control valve causes a variation in the pressure and density and hence in the quantity of the oxygen supplied to the mixing chamber; the same decreasing with the openingy of the valve and increasing with' the closing thereof. Under these conditions, if the valves controlling oxygen and fuel supply to the mixing chamber are originally set for a neutral Umixture Vwith the control valve for the cutting-oxygen closed, opening vof this latter valve will cause the preheating ame to become carbdnizing. On the other` hand, if the preheating flame is originally adjusted to neutral with the cutting oxygen con-4 trol Valve open, upon closing this valve, the

whereby the flow of gas in one of the passages.

is under automatic control of that in another passage.

A still further object of the invention is to provide, in acuttingyblowpipehaving a plurality of'passages for conducting gases to a tip and means for diverting a portion of the gas fromI one of the passages to another for mixing with titative supply of oxygen to the fuel passage inl apparatus of the above character may be maintained constant and the preheatng ilame therefore neutral by provision of means whereby the Volume of oxygen passedY from the main oxygeln passage to the fuel passage is varied in such inverse ratio to the pressure, and density of gas within the main oxygen passage on the intake side of the valve incontrolthereofpthat the actual quantity of gas so passed in unit \time will be unvaried. Such means may comprise a valvel in control of the passage of gas through the branch or oitake passage, the opening and closing of which is eiected by pressure responsive means, as a flexible diaphragm under inuence of the variations of gaspressure in the Vmain oxygen passage.v

The above and other objects and novel features of the invention will become apparent from the following speciiications taken with the accompanying drawing, in which,

Fig. l1 is a view in longitudinal section through a cutting torch; the same being shown fragmentarily and illustratingone embodiment ofr the invention; and y .t

Fig. "2 is a fragmentary view vsimilar to Fig. llr showing a somewhat 'different form of the invention. Y

The invention is illustrated in the accompanying drawing as applied to a cutting blowpipe although the same is applicable to any analogous vdevice in which it is desired to regulate the flow of i'luid through one conduit byI means of that owing throughanother conduit. The blowpipe, as illustrated comprises a head 10fha`ving the. customary tip IT attached thereto; the head being suitably connected, as by conduits 12 and i 13, to a handle H. The handle I- is comprised of a hollow casing ll'and a valve block or casting B secured in the rear end thereof; the block passage 12a, and passage F with conduit 13 through a passage A17 and a mixing chamber 18 at the forward end of passage 17. The cross pasnozzle 19 where it is intermingled with oxygenrin the mixing chamber 18 to form a combustible mixture.

`Flow of oxygen through branch passage 20 may be regulated through throttle valve 22 operable through a hand wheel 22a and flow of fuel gas through passage F by throttle valve 23 operable through handwheel 23a. Flow of cutting oxygen to the tip T through passages O, 12a and conduit 12 is under sensitive control of the operator through al valve 24 slidably mounted in passage O and normally held closed against its seat 25 which is located within said passage and is held between a shoulder 26 and an annular locking screw 27 threaded into thepassage. The

valve 24 is yieldably held closed against its seat by a helical spring 28abutting at its ends respectively the rear end of the valve and the front end of tube 15; the latter being recessed to provide a seat therefor. The valve 24 may be opened by the operator against the force of spring 28 by depression of a lever 29 pivoted at 30 within the casing and acting against the end of a valve stem 34 slidably mounted in the bore of a plug 35 which serves to close an opening in the front end of passage O. Lever 29 is operable from outsidel of casing 11 by depression of a'. thumb button 31 connected to the lever by a lug 32 extending through an opening 33 in the casing and the lever maybe latched in depressed position by engagement of the edge of the casing wall which defines the opening 33, in a notch 32a formed in the lug. c

The construction so far described is common to the present invention and to blowpipes heretof ore known and such construction, without the improvements constituting the present invention, is subject to the disadvantages as outlined above. These disadvantages are overcome, in the present invention, as illustrated in Fig. 1, by provision, in additionto valve 22 in the branch passage 20, of a second valve 36 in automatic control of the gas flow through the branch passage. Valve 36 is operated in its controlling movements by the variations in gas pressure on the outlet side of valve 24 in passage O; said variations being `communicated to the valve through regulator means which may include pressure responsive means, as a diaphragm 37 the center of which is connected to the valve by means of the valve stem 38.A The stem is arranged to extend through a passage 39 forming communication between the branch passage 20` and a recess 40 formed in the block and communicating with cross passage 12a. The dia-I phragm 37 ispositioned across this recess and is held in place between a shoulder 41 formed in the recess by counterboring the same and a ring screw 42 threaded into the counterbore..

The valve 36 may be of conical contoury and may be provided with a similar shaped seat in branch passage 20. 'I'he valve is preferably formed in its base with a recess 43 t'o accommodate one end of a helical spring 44'the other end thereof seating against a shoulder 45 formed on a pin 46. This pin is adjustably mounted for varying the tension of the spring and to this end is threaded into the bore of a plug 47 which is threaded into and serves `as a removable closure for an opening leading into branch passage 20 andpositioned opposite the valve 36 so as to aord access thereto for servicing purposes. One end of the pin 46 is projected into the spring 44 and the otherend projects rearwardly through a stuling boX 48 to a point beyond the block and is provided with means, as a kerf 49, whereby the pin'may be engaged by a tool for varying the compression of the spring and determining thereby the responsiveness of the diaphragm to changes of pressure in the cross passage 12a. Valve 36, in use, is adjusted to stand open to anv extent to freely pass the quantity of gas normally required for providing a mixture with the fuel gassuch as will produce a neutral ame.

'Ihe valve 36 may be adjusted for giving a neutral llame either with valve 24 open or closed. In either case its operation in regulating the ow of gas through the passage 20 will be the same. If the pressure rises in passage 12a xits seat permitting the passage of a decreased volume of the oxygen which, as -a consequence of closing valve 24, is obviously of increased density. By a proper adjustment of spring 44 the opening and closing of valve 36 may be regulated to exactly compensate for the uctuation of gas density in the passage 20 on the intake side of this valve and of valve 24.

Suitable openings may be provided in the block or,y casting B opposite the diaphragm 37 andO nozzle 19 which provide access thereto for servicing the same and these openings may be closed` by removable plugs 50 and 51 respectively. v

The blowpipe construction illustrated in Fig. l2 varies from that in Fig. 1 primarily in that valve 36 is positoined to be actuated, in its valve regulating movements, by variations in gas pressure in passage O on the intake side of valve 24. To this end, the diaphragm 37 is located in an opening in the wall of passage O on the intake side of valve 24 and is held in place between a shoulder 52 formed internally of a ring screw 53 threaded into the opening and the end of the shank of a screw 54 threaded into the ring screw; The shank of screw 54 is recessed at its end Opposite the diaphragm to accommodate movements of the diaphragm and its head is provided with an aperture 55 forming communication between the recess and the atmosphere. 'I'he valve 36 is connected with the diaphragm by means of the stem 38a which is provided with a portion projecting above the mixture.

screw and diaphragm. Ring screw 53 is provided with an extension 59 which bridges passage Oand has attached thereto a member 60 seated in a recess around the mouth of passage and provided with a port therethrough surrounded by a seat 61 for Valve 36.

In this second form of the invention, supplying of gas through branch passage 20 to the mixing chamber may be under control of valves 36 and 22 only; valve 22 serving to open or close completely the passage 20while valve V36 is regulated through screw 5.7 to admit the normal volume of gas required for the combustible passage 0-on the intake side of valve 24 decreases thereby, with proper adjustmentof the compression spring 58, maintaining the quantity of gas passed by this valve into passage 20 constant. However, it is preferable that the main volume of oxygen to be passed through passage 20 to the mixing chamber be supplied to passage 20 through a port which when: set for passing a given volume of gas will not be varied except at the will of the operator. There is therefore, provided in the casting B a passage 62 bypassing the valve 36 and controlled by a throttle valve 63 which may be set for the normal amount of gas required, whereupon the compression of spring 58 may be so adJusted that valve 36 will be closed when valve 24 is closed and may serve to pass such supplemental gas only as is necessary to maintain the quantity passed in unit time through passage 20 constant.

Valve 24 is normally held closed by a spring 28 and a ring screw `64 is threaded into the passage O tov form a rear abutment for' this spring.

In operation, this form of the invention is substantially the same in principle as that shown in Fig. 1 except that valve 36 is operated under variations in pressure on the intake instead of the exhaust side of valve 24. q

By means of a construction such as provided in either of the above described embodiments the supply of oxygen to the mixing chamber is maintained substantially uniform and the objectionable results of an oxidizing and carbonizing preheating flame are avoided.

l. A member having gas passages therethrough; a cross passagebetween said passages; means under inuence ofthe gas in one of the Ist-named passages for maintaining quantitathrough; means for supplying gas from one of said passagesA to 'another and regulatory means acting responsively to variations in gas pressure' in the passage from which the gas`v is supplied 4so constructed and arranged as to maintain the gas supplied quantitatively constant. p

4. A member having gas passages therethrough; and means for passing gas from one passage to another and regulator means for con- Under these conditions, valve 36 will l y"open further in proportion as the pressure in trolling the gas passed so constructed and arranged that the volume of gas passed will vary inversely as the gas density in the passage from which the gas is passed.

5. A member vhaving gas passages there-- f gas passages leading to said tip; a passage providing communication between the first-named passages and a valve for regulating the flow of gas in one of the passages'under iniiuence of gas pressure in another of said passages; said valve being so constructed and arranged that the quantitative Vflow of gas in the regulated passage will be maintained constant.

P7.l[n a blowpipe, the combination of a tip;

gas passages having a common source of gasV supply leading to said tip; a valve for regulating the ow of gas in `one of the passages; and pressure responsivemeans under influence of the gas in another of said passages for controlling said valve; said pressure responsive means being so constructed and arranged as to maintain the quantitative flow of gas from the common source in said valve controlled passage constant.

8. In a blowpipe, lthe combination of a tip; communicating gas passages for conducting gas thereto and means operating under control of gas pressure in one of the passages for main-- taining the quantitative flow of gas from one of said passages to the other constant.

9. In a blowpipe, the combination of a tip; a pair of passages for conducting fluid to the tip; a passage for conducting gas from one of said passages to the other; and means for' maintaining the quantity of gas so conducted in a unit of time constant; said means being operable by the gas pressureiin the passage from which the gas is passed.

10. In,a blowpipe, the combination of a tip; a pair of passages for conducting gas to the tip; a branch passage for conducting gas from one of said passages 'to the other; and means for maintaining the quantity of gas so conducted in a unit of time constant; said means being operable by the gas pressurein the passage from which the gas is conducted at a point between said branch passage and the tip.

11. In a; cutting blowpipe, the combination of a tip; an oxygen and a fuel gas passage leading thereto; a branch passage leading from the oxygen passage to the fuel gas passage; and pressure responsive means under influence of pressure in the oxygen passage for controlling the flow of oxygen through the branch passage; said pressure responsive'means being so constructed and arranged as to maintain the oxygen transferred from theoxygen to the fuel passage quantitatively constant.

IRI

12. In a cutting blowpipe, the combination of mixture quantitatively constant under influence of the gas pressure in the cutting oxygen passage.

13. In a cutting blowpipe, the -combination of a tip; a passage for cutting oxygen leading from a source and a passage `for a combustible gas leading to the tip; means for feeding oxygen into the combustible gas from said source to provide a combustible mixture and means whereby the now of oxygen into the combustible gas is controlled by the passage of oxygen through the cutting oxygen passage; said last named means being so constructed and arranged that the oxygen fed to the combustible gas will be maintained quantitatively uniform.

14. In a cutting blowpipe, the combination of a tip; an oxygen and a fuel passage leading thereto; a branch passage from the oxygen passage to the fuel passage; a valve for controlling the flow of oxygen through the oxygen passage; and means under influence of gas pressure in the oxygen passage between the tip and said valve for regulating the flow of oxygen through the branch passage; said last namedmeans being so constructed and arranged that the oxygen fed to the combustible gas will be maintained quantitatively uniform.

15. In a cutting blowpipe,'the combination of a tip; a passage for conducting oxygen to the tip from a source of supply; a passage for conducting fuel gas to the tip; a valve in the oxygen passage controlling the flow of oxygen therethrough to the tip; a branch passage leading from the oxygen passage to the fuel passage from a point between the source of supply and the valve; and means so constructed and arranged that it will operate under influence of the gas in the oxygen passage between the valve and the tip for maintaining the quantity of oxygen delivered through the branch passage in a unit of time' to the fuel passage constant.

16. A member having a pair of gas passages therethrough; a valve controlling the yflow of gas through one of said passages; a branch passage from the valve controlled passage for feeding gas continuously to the other of said passages; and means so constructed and arranged that it will effect the feed of an `'adidtional volume of gas from the valve controlled passage to the other passage when the valve is open.

17. A member having gas passages therethrough; a valve for controlling passage of gas through one of the passages; a second passage; a branch passage for passing gas continuously from the intake side of the valve in the valve controlled passage to the second passage; and means so constructed and arranged as to cause an additional volume of gas to be passed from the valve controlled passage to the second passage when gas is admitted to the exhaust side of said valve in the valve controlled passage.

18. In a blowpipe having'a tip and gas passages leading thereto; the combination of a valve controlling flow of gas4` through one of said passages; means for passing gas 4from the valve controlled passage to the other passage; and,

means for regulating the volume of gas passed responsive to the pressure in the valve controlled passage on the intake side of the valve.

19. In a metal cutting blowpipe adapted to deliver an Oxy-fuel gas preheating mixture and an oxidizing gas for cutting, the combination of a passage for supplying the fuel gas; an oxidizing gas passage adapted to supply oxidizing gas;

and means for delivering oxidizing gas from said oxidizing gas passage both for mixing with said fuel gas and for cutting and so constructedl and arranged that a predetermined quantity of oxidizing gas may be constantly supplied for mixing with the fuel gas irrespective of the quantity of oxidizing gas delivered for cutting.

20. In a metal cutting blowpipe adapted to deliver an Oxy-fuel gas preheating mixture and \an oxidizing gas for cutting; the combination of and arranged that a predetermined quantity of oxidizing gas may be constantly supplied for mixing with the fuel gas regardless of whether oxidizing gas is or is not being delivered for cutting.

' ROBERT J. KEHL. 

